Scientists assessed the effectiveness of prophylactic capsular tension ring implantation during cataract surgery in highly myopic eyes, as part of a prospective cohort study.

Consecutive highly myopic patients treated with cataract surgery were recruited and randomized to undergo CTR implantation or not. The outcomes compared between the two groups included axial lens position (ALP), intraocular lens decentration and tilt, area of anterior capsule opening, severity of anterior capsular opacification and posterior capsular opacification at one year after surgery.

A total of 55 highly myopic eyes with CTRs implanted and 55 without were included in the analysis. Here are some of the findings at one year after surgery:

• No significant differences were detected between CTR and non-CTR groups for the mean ALP, IOL decentration or tilt (all p>0.05). 
• The CTR group had a significantly larger area of anterior capsule opening (23.62 ±3.30 mm² vs. 21.85 ±2.30 mm²; p=0.003), and less severe ACO (p=0.033) and PCO (PCO-3 mm: 0.06 ±0.13 vs. 0.13 ±0.20; p=0.038; PCO-C: 0.15 ±0.18 vs. 0.25 ±0.26, p=0.026) than the non-CTR group. 
• The corrected distance visual acuity, prediction error and higher-order aberrations didn’t differ between the two groups (all p>0.05).

Scientists wrote, in highly myopic eyes, although prophylactic capsular tension ring implantation reduced the severity of capsular contraction and opacification, it didn’t significantly affect postoperative IOL stability or visual outcomes.

^{J Cataract Refract Surg 2024; May 29. [Epub ahead of print].}

^{Hu X, Qi J, Cheng K, et al.}

Accuracy of New IOL Formulas

Scientists evaluated the accuracy of a new intraocular lens power calculation formula using segmental refractive index-based axial length (AL), as part of a retrospective observational study.

The study included patients undergoing preoperative examination for cataract surgery with the new Barrett True AL (BTAL) and Emmetropia Verifying Optical (EVO) formulas using segmental refractive index, and conventional Barrett Universal II (BU II) formula using equivalent refractive index. The predicted refractive error of each formula was compared with the postoperative subjective spherical equivalent.

Here are some of the findings: 

• The mean prediction error in the short AL group (≤ 22 mm; 44 eyes) was: 

– 0.32 ±0.40 D for BU II; 

– 0.22 ±0.37 D for BTAL; and 

– 0.10 ±0.37 D for EVO (p<0.0001). 

• Mean prediction error in the long AL group (≥ 26 mm; 92 eyes) was: 

– 0.01 ±0.32 D for BU II; 

– 0.04 ±0.32 D for BTAL; and 

– 0.09 ±0.32 D for EVO (p<0.0001). 

• In patients with an AL ≥28 mm, BU II showed a myopic trend in 57.1 percent of cases, while BTAL and EVO showed a hyperopic trend in 71.4 percent. 

• The mean prediction error for patients with an AL ≥28 mm was: 

– -0.16 ± 0.34 D for BU II; 

– 0.18 ± 0.33 D for BTAL; and 

– 0.16 ±0.32 D for EVO (p<0.0001).

Scientists reported the new Emmetropia Verifying Optical and Barrett True AL formulas showed higher accuracy than Barrett Universal II in short eyes, while no difference was found in long eyes.

^{J Cataract Refract Surg 2024; May 1. [Epub ahead of print].}

^{Kato Y, Ayaki M, Tamaoki A, et al.}

Different Ways to Assess GA Analyzed

Investigators compared the inter-modality and -reader agreement of manual and semiautomated geographic atrophy area measurements in eyes with GA due to age-related macular degeneration using conventional blue and ultra-widefield (UWF) green light fundus autofluorescence (FAF) systems.

FAF images of eyes with GA were obtained during a single visit using the Spectralis HRA+OCT2 device and the Optos California device. Images were exported for masked analysis by two independent masked graders. The area of the GA lesions was segmented and quantified (mm²) with a fully manual approach while the lesions were outlined using Optos Advance and Heidelberg Eye Explorer (HEYEX) software. For the Heidelberg blue FAF images, GA lesions were also measured using the instrument’s semi-automated software (Region Finder 2.6.4). To compare modalities/grading, mean values of the two graders were used. Intraclass correlation coefficients (ICC) were computed to judge the agreement between graders.

A total of 72 eyes of 50 patients were included. Here are some of the findings: 

• Nearly perfect agreement was found between graders for the measurement of GA area for all three modalities (ICC=0.996 for manual Optos Advance, 0.996 for manual Heidelberg HEYEX and 0.995 for Heidelberg Region Finder). 

• The measurement of GA area was strongly correlated between modalities, with Spearman correlation coefficients of:

– 0.985 (p<0.001) between manual Heidelberg and manual Optos; 0.991 (p<0.001) for Region Finder vs. manual Heidelberg; and 

– 0.985 (p<0.001) for Region Finder vs. manual Optos. 

• The absolute mean area differences were (p<0.001 for all three):

– 1.61 mm² for Heidelberg manual vs. Region Finder;

– 0.90 mm² for manual Optos vs. Region Finder; and

– 0.71 mm² for manual Optos vs. manual Heidelberg.

Investigators observed excellent inter-reader agreement for geographic atrophy measurement using either 30-degree blue FAF or UWF green FAF, establishing the reliability of UWF imaging for macular GA assessment. However, though the absolute measurements between devices were strongly correlated, they differed significantly, highlighting the importance of using the same device for a given patient for the duration of a study.

^{Ophthalmol Retina 2024; Apr 24. [Epub ahead of print].} 

^{Abbasgholizadeh R, Habibi A, Emamverdi M, et al.}

Deep Learning for Analyzing Glaucoma Progression

Researchers developed a deep learning (DL) algorithm to detect glaucoma progression using optical coherence tomography images, in the absence of a reference standard, as part of a retrospective cohort study.

Glaucomatous and healthy eyes with ≥5 reliable peripapillary OCT (Spectralis, Heidelberg) circle scans were included. A time-series learning model, called Noise Positive-Unlabeled (Noise-PU) DL, was developed to classify whether sequences of OCT B-scans showed glaucoma progression. The model used two learning schemes, one to identify age-related changes by differentiating test sequences from glaucoma vs. healthy eyes, and the other to identify test-retest variability based on scrambled OCTs of glaucoma eyes. Both models’ bases were convolutional neural networks (CNN) and long short-term memory (LSTM) networks combined to form a CNN-LSTM model. Model features were trained to identify glaucoma progression, accounting for age-related loss. The DL model’s outcomes were compared with ordinary least squares regression of retinal nerve fiber layer thickness over time, matched for specificity. The researchers used the hit ratio as a proxy for sensitivity.

A total of 8,785 follow-up sequences of five consecutive OCT tests from 3,253 eyes (1,859 subjects) were included. Mean follow-up time was 3.5 ±1.6 years. In the test sample, the hit ratio of the DL method was 0.498; CI, 0.470 to 0.526; and the hit ratio of the ordinary least squares was 0.284; CI, 0.258 to 0.309 (p<0.001) when the specificities were equalized to 95 percent.

Researchers wrote that a deep learning model was able to identify longitudinal glaucomatous structural changes in OCT B-scans using a surrogate reference standard for progression.

^{Am J Ophthalmol. 2024 May 2. [Epub ahead of print].}

^{Mandal S, Jammal AA, Malek D, et al.}

Image-guidance Systems Used With FLACS Studied

Scientists evaluated the effectiveness corneal astigmatism correction using the Alcon Image Guidance system vs. manual marking in the orientation of femtosecond laser-assisted astigmatic keratotomy incisions, as part of a retrospective review of patients undergoing femtosecond laser-assisted cataract surgery from January 2018 to June 2022.

Patients who underwent FLACS with and without image guidance (IG) were investigated. Variables including preoperative K values, cylinder, spherical equivalent (SE) and visual acuity were collected, as well as the cyclorotation angle delta registered by image guidance, postoperative refractive cylinder, SE and VA. The primary outcome was postoperative refractive cylinder in patients with IG vs. those without IG.

A total of 160 eyes were included; 103 eyes had IG, and 57 eyes didn’t. 

• Postoperative cylinder was similar in those with image guidance (0.31 ±0.36 D) compared to those without image guidance (0.31 ±0.37 D)(p=0.97). 
• Average cyclorotation in the image guidance group was 2.82 ±3.03 degrees. 
• When cyclorotation was stratified into three groups (<2.8 degrees, 2.8 to 8.5 degrees, >8.5 degrees), no differences were found in postoperative refractive cylinder (p=0.35).

Scientists wrote that patients who underwent femtosecond laser-assisted cataract surgery with image guidance had similar postoperative cylinder outcomes compared to those without image guidance. 

The researchers noted the findings suggested the accommodation of cyclotorsion using an advanced image guidance system in FLACS was similar to that obtained with manual marking techniques in cataract patients having 2 D or less of astigmatism corrected. 

^{J Cataract Refract Surg 2024; May 9. [Epub ahead of print].}

^{Yalamanchili SP, Cleary SM, Sell SS, et al.}